Participants in this study received an intrathecal drug delivery system implant between 2000 and 2013.

Intrathecal drug delivery systems may be ineffective in reducing pain and oral opioid intake in individuals with complex regional pain syndrome, according to a study recently published in Pain Medicine.

This study included 1653 individuals with implanted intrathecal drug delivery systems, 62 of whom had received the device to alleviate complex regional pain syndrome-related pain (n=26 with ≥ 4 years of follow-up data). Participants in this study received an intrathecal drug delivery system implant between 2000 and 2013. The primary outcomes for this study included pain intensity and oral intake of opioids.

Pain scores showed no significant decrease over time, and no correlation was established between the use of any intrathecal medication and pain intensity. Oral opioid use was found to be reduced over time, but was unaffected by the dose of intrathecal opioids. Ziconotide use was associated with a more rapid decrease in consumption of oral opioids, but bupivacaine led to increased consumption.

“[I]ntrathecal opioid dose was not associated with long-term decreases in oral opioid intake. Additionally, ziconotide was associated with a decrease in oral opioid intake over the four-year follow-up, and bupivacaine was associated with an increase in oral opioid intake…. Our findings suggest that intrathecal opiates may not be effective in reducing oral opiate intake; ziconotide may hasten a decrease in intake; and bupivacaine may lead to an increase in intake,” concluded the study authors.